Process for the manufacture of metallic beryllium or its alloys



Patented June 9, 1931 UNITED STATES PATENT OFFICE HELLEUT FISCHER, OF IBERLm-FRIEDENAU, GERMANY, ASSIGNOR BY MESNE AS- SIGNMENTS, TO METAL & 'l'IBIIlirRMI'I CORPORATION, OF NEW YORK, N. Y., A COR- PORATION 01 NEW JERSEY PROCESS FOR THE MANUFACTURE OF METALLIC BERYLLIUM OR ITS ALLOYS No Drawing. Application filed October 3, 1927, Serial No. 223,835, and in Germany October 7, 1926.

This invention relates to a new process for the manufacture ofmetallic beryllium or its alloys by the electrolysis of molten materials, which process is suitable for the production 5 of beryllium or beryllium alloys both in a compact form and in the form of coatings.

Of the processes hitherto known for the manufacture of metallic beryllium the only one which has been found to be of any use technically is that of Stock & Goldschmidt. In this process the beryllium is separated by the electrolysis of molten materials from a molten mass composed of a mixture of double fluorides of beryllium with alkaline earth metal fluorides and alkali metal fluorides. The known process however is attended by difliculties inasmuch'as on the one hand the preparation of the double fluorides required is a complicated and expensive procedure and, on the other hand, a not-inconsiderable loss frequently takes place during the work ing of the process owing to volatilization.

Similar difficulties are encountered'in the manufacture of beryllium alloys or coatings of beryllium when the above mentioned molten mass is employed.

The object of the present invention is to eliminate the aforesaid inconveniences. This is achieved according to this invention by using as an integral part of the molten mass (instead of double fluorides) a simple oxygenated beryllium fluoride, that is, either basic beryllium fluoride or beryllium oxyfluoride mixed with one or more alkaline earth metal fluorides with the addition if necessary of alkali metal halides.

By the term basic beryllium fluoride I designate such intermediate compounds,'con-. taining a greater or smaller proportion of oxygen, which are formed during the preparation of beryllium oxyfluoride from normal beryllium fluoride, BeF According to Lebeau (Comptes Rendus, vol. 126, 1898, page 1418) the formula for beryllium oxyfluoride is 5BeF .'BeO. So far as I am aware, no exact formulae are available for basic beryllium fluoride.

The molten mass used in the new process, which contains a high percentage of beryllium, is considerably easier and cheaper to prepare than the beryllium compounds used' for the molten mass of the known process,

The liability of the new molten mass to volatilizations is also considerably less. To supplement the electrolytically decomposed beryllium salt, basic beryllium fluoride or beryllium oxyfluoride may be added as the process proceeds. The addition of alkali metal fluorides lowers the viscosity of the mass. If necessary beryllium oxide may also be added to the new molten mass while the process is being worked. The solubility of the beryllium oxide in the new molten mass is considerably greater than it is in the molten mass employed in the older known process.

The oxygenated beryllium fluoride is preferably prepared separately and then mixed with the earth alkali metal fluoride.

The electrolysis of the molten substances is carried out according to the new process conveniently at a temperature above the melting point of beryllium (i. e. about 1285 (l). The volatilization of the electrolyte is notwithstanding comparatively very slight at this temperature. A further and important advantage of the new process is that the volatilizing salts, which in accordance with a further feature of the invention, are almost completely recovered, can be returned directly to .the electroylsis again. The electrolysis of the molten substances when once made up and adequately saturated as the process proceeds with beryllium salts or flue dust can be carried on as long as may be desired. The new process therefore enables the work to be carried on continuously, almost without any lossby volatilization, as, apart from slight losses in the volatilizing salts at the beginning only an addition of the beryllium salts decomposed by the electric current is necessary.

To prepare compact metallic beryllium the new process may be carried out for example as follows from being melted or burned, the cathode may be provided with means for cooling it by a high tension electrodes,

up the molten mass.

water. The beryllium is separated at the cathode in a very pure compact form. At suitable intervals of time as the bath becomes poor in beryllium, if necessary some barium fiouride, the latter to replace the barium'salt which has been volatilized, is added. The volatilized salts are trapped by means of a suitable apparatus e. g. a dust chamber or on continuous current and the sublimation product either alone or if necessary together with fresh beryllium oxyfluoride used to make The electrolysis can be continued as long as may be desired only the beryllium regulus which is separated at the cathode must be removed from time to time according to the size of the bath in the crucible.

If the new process is to be used for the production of beryllium alloys, it is advisable to use the metal to be alloyed with the beryllium in the form of a liquid cathode and to otherwise carry out the process as in the above example. To produce coatings of beryllium the article to be coated is introduced as a cathode into the molten mass and if necessary it may be cooled. In the production of beryllium coatings it is advantageous under some circumstances, to use an intermediate layer which consists of another metal. Such intermediate layers may be produced galvanicall for example and the metals and alloys w are those the melting points of which lie considerably above that of beryllium, e. g. tungsten, molybdenum, tantalum, vanadium, niobium, etc. suitable for the intermediate layer are iron, copper, After the intermediate layer has been applied to the article to be coated-this latter is connected up as the cathode, introduced into the new molten mass and this latter then subjected to electrolysis at a temperature of about 700 to 1200 C. It is also possible it it be required, to produce coatings of alloys of beryllium with or without an intermediate layer. This may be done for example by adding the'salt of a suitable alloying metal, such as aluminium for example, to the now molten mass. The metals which mainly are suitable for the production of beryllium alloys in a compact form or in the form of coatings are aluminium, copper, magnesium, nickel, cobalt, iron etc.

What I claim as my invention and desire to k be secured by Letters Patent is 1. In. the production of electrodeposited coatings containing beryllium, the process beryllium .oxyflouride and ich are best suited for this purpose which comprises electrolyzing a molten bath molten bath also contains compounds selectedfrom a class consisting of alkaline earth metal fluorides and alkali metal fluorides.

3. The process of claim 1 in which the beryllium compound employed is beryllium ox fluoride.

n testimony whereof I aflix my signature.

HELLMUT FISCHER.

Materials which are'particularly nickel, cobalt and others besides. 

